The JPL EC-16 Ear 70mm ear cushion fits onto JPL-401S/402S, JPL-501S/502S, JPL-611, JPL-Connect, JPL-HAC, TT3-Avant, JPL-Explore and BT500D headsets. Surrounding your ear with the large cushion to allow you to concentrate on the call and not be distracted by conversations around you. Once you have removed the existing ear cushion, the EC-16 70mm ear cushion simply clips onto the speaker holder. Not only does changing the pads have hygienic merit, but it also helps to preserve the original sound intended. Even if the pads are clean, they become compressed as they age, and this alters the effective acoustic space.